Packet capture is a unit of data that is routed between an origin and a destination on the web or any other packet-switched network. When any file (such as e-mail message, HTML file, Graphics Interchange Format file, Uniform Resource Locator request) is sent from one place to a new destination, the Transmission Control Protocol (TCP) layer of TCP/IP splices the file into smaller chunks which make it more optimized and ideal for routing.

Traditional (or what we will call legacy network traffic analysis) NTA solutions based on packet capture require large investments of time and money to get up and running with their required installations of special sensors.